package java3_3;
/**
 * 5：求1-20之间的数的乘积(double)
 */
public class homework3 {
    public static void main(String[] args) {
        long i = 1;
        long x = 1;
        while (i<=20){
            x = x*i;
            i++;
        }
        System.out.println(x);
    }
}
